suggest boolean expressions for "-wp-prop" arguments
ID0002285: This issue was created automatically from Mantis Issue 2285. Further discussion may take place here.
|ID0002285||Frama-C||Plug-in > wp||public||2017-02-27||2019-10-17|
|Reporter||Jochen||Assigned To||correnson||Resolution||won't fix|
|Product Version||Frama-C 14-Silicon||Target Version||-||Fixed in Version||-|
Currently, the semantics of "-wp-prop" arguments is unexplained and difficult to understand, when negation and more than one label is used.
For example, using the attached file, "-wp=prop=A,B,-C" selects l4,l5,l6, whereas "-wp-prop=-C,B,A" selects all but l3, and so does "-wp-prop=A,B,c" (although the set of "C"-labelled lemmas is the complement of that of the "c"-labelled lemmas).
I think, parsing arbitrary boolean expressions (built from "!", "&&", "||") isn't more difficult that the current mechanism, but is easier to describe in the manual and to understand.
Alternatively, "-" could be kept as negation, "," could be used for cunjunction only, and the results of multiple args "-wp-prop=X -wp-prop=Y" could be or-ed together; this would at least allow to express arbitrary sets in disjunctive normal form.
Additional Information :
Complex set expressions arise when labels are used during proof development to attach prover names (and even options) to properties. Using calls like "frama-c -wp -wp-prop=PROVE_WITH_CVC4 -wp-prover=cvc4 ..." can save a lot of proving time that is normally wasted by unsuccessful attempts by unsuitable provers. Other labels that can save time are "TODO", "NEEDS_LONG_TIMEOUT", etc. This way, boolean expressions arise in a natural way; and the user needs to be sure about their semantics, in order not to overlook proof obligations due to splitting by prover.